20636540 has 24 divisors (see below), whose sum is σ = 43490832. Its totient is φ = 8225280.

The previous prime is 20636513. The next prime is 20636549. The reversal of 20636540 is 4563602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20636549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4460 + ... + 7820.

It is an arithmetic number, because the mean of its divisors is an integer number (1812118).

Almost surely, 2^20636540 is an apocalyptic number.

20636540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20636540 is an abundant number, since it is smaller than the sum of its proper divisors (22854292).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20636540 is a wasteful number, since it uses less digits than its factorization.

20636540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3677 (or 3675 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 26.

The square root of 20636540 is about 4542.7458656632. The cubic root of 20636540 is about 274.2914652915.

The spelling of 20636540 in words is "twenty million, six hundred thirty-six thousand, five hundred forty".